Molded articles made of a fiber-reinforced resin obtained by mixing functional fibers such as carbon fibers with a resin are widely used in transportation equipment materials for automobiles and aircrafts, civil engineering and construction materials and sports goods since they are excellent in characteristic properties such as weatherability, mechanical strength and durability.
For example, Patent Document 1 below discloses a carbon fiber-reinforced resin molded article containing a specific pitch-based carbon short fiber mixture and a matrix resin and teaches that it is advantageously used in various electronic parts.
Patent Document 2 below proposes a friction material made of a resin composition for friction materials containing a specific aromatic polyimide oligomer as a binder for carbon fibers. Patent Document 2 teaches that the heat resistance and mechanical properties of the binder itself are excellent and moldability is high in this friction material as compared with a case where a phenol resin which has been advantageously used as a binder for friction materials is used.
Further, Patent Document 3 below proposes a rolling body made of a carbon fiber-reinforced synthetic resin containing 10 to 70 wt % of carbon fibers having a specific thermal conductivity.
When this fiber-reinforced resin molded article is used as a sliding member such as a bearing, characteristic properties including high mechanical strength such as strength and stiffness, a small dynamic friction coefficient, a small wear volume and further a large limit PV value are required, and it is desired that an addition reaction type polyimide resin which is excellent in mechanical strength, heat resistance and durability as well as the impregnation property of a resin should be used as a matrix resin.
There is also proposed a highly functional addition reaction type polyimide resin which makes it possible to produce a carbon fiber-reinforced composite by transfer molding (RTM) and resin injection (RI) as an addition reaction type polyimide resin (Patent Document 4).